This invention relates to an image-sensing control method, image-sensing apparatus and image-sensing system, for transmitting still image information or moving image information between terminals at remote places connected via a network or a public telephone-line network, and a storage medium containing a program for executing the image-sensing control method.
These days, many visual-telephone and teleconference systems employ an ISDN line. The ITU-T H. 320 Recommendations include the N-ISDN AV (Audio Visual) system configuration and terminal construction. Further, the recommendations on the telephone line network are now being developed to cover a general public telephone-line network, as recommendations H. 324 on a low-bit rate visual-telephone multimedia terminal.
The multimedia terminal or a representative element for the visual-telephone and teleconference system is a video camera which inputs a sensed video image. The video camera includes a camera placed on a pan head such that the video camera can be freely rotated in a horizontal direction or a vertical direction in accordance with an external control signal. In addition, a video camera integrated with such pan head is known. In a visual-telephone and teleconference system using the video camera integrated with the pan head or the pan head, the image sensing direction of a video camera at a remote place, e.g., a video camera of a communication-destination terminal, can be remote-controlled. FIG. 7 shows an overview of the video camera integrated with the pan-head. In this video camera, a camera 70 is placed on a pan head 72. The video camera may have another arrangement where the camera 70 can be separated from the pan head 72.
In the conventional visual-telephone and teleconference system, if the video camera of the communication-destination terminal is not placed on a remote-controllable pan head, e.g., in a case where the video camera initially set on the pan head is removed from the pan head, or in a case where the image sensing direction of the video camera cannot be remote-controlled, the status of the camera of the communication-destination terminal cannot be determined. Especially, there is no way of determining whether or not the video camera is placed on the pan head, otherwise, even if it is placed on the pan head, whether or not the pan head can be remote-controlled cannot be determined. This is very inconvenient for controlling the video camera of the communication destination station.